This week’s reality onslaught continues with “Dance Machine” (7 p.m., ABC), another talent hunt offering “ordinary” people the chance to show off their talent for dancing in a variety of genres from the past four decades.

If this sounds familiar, it should be, because just a few weeks ago, TLC introduced something called “Master of Dance,” hosted by Joey Lawrence. It’s easy to confuse the two – or forget the two, for that matter.

The “Dance Machine” set looks a little fancier, but they both look like hand-me-downs from canceled game shows. The contestants on the TLC show appear to be a little closer to “real” people than the ones on “Dance Machine,” where the first “ordinary” person to stand out is described as “a mixed martial artist from Las Vegas.” Maybe I live in a dull part of the universe, but in my town, that doesn’t qualify as “ordinary.”

The networks seem to be learning all of the wrong lessons from cable. A show like “Master of Dance” works on cable because both cable programmers and cable viewers don’t have any expectation that people will work their schedule around the show. Viewers know it will be repeated with annoying frequency, and sooner or later they will succumb and finally watch it.

Many of the biggest cable hits became popular with endless exposure. “Project Runway” was a bit of a flop at first and took off only when Bravo carpet-bombed its weekend schedule with so many repeats of “Runway” that the habit stuck.

Networks, on the other hand, have viewers and sponsors with different expectations. If ABC repeated “Dance Machine” seven times during the course of a week, we’d all be upset and rightly so. One has to wonder why a network chooses to compete with cable in this fashion when the rules are rigged against it.

¢ Turner Classic Movies salutes the life of Cyd Charisse, the dancer who recently died at the age of 86. The three-movie tribute includes the 1952 musical “Singin’ in the Rain” (7 p.m., TCM); “The Band Wagon” (9 p.m.) from 1953; and “Silk Stockings” (11 p.m.), a 1957 musical adaptation of “Ninotchka.” “Rain” pairs Charisse with Gene Kelly. In the final two films, she dances with Fred Astaire. Even if you’re not a huge fan of movie musicals with big dance numbers, you owe it to yourself to catch “The Band Wagon,” or at least the extensive dance number with Charisse and Astaire offering a brilliant parody of the Mickey Spillane detective novels that were popular at the time.

Tonight’s other highlights

¢ The 19th Annual GLAAD Media Awards (6 p.m., Bravo) salutes fair representation of gay life in media and entertainment.

¢ Ice Cube stars as a super Secret Service agent in the 2005 thriller “XXX: State of the Union” (7 p.m., Fox).

¢ “Hallmark Heroes with Regis Philbin” (7 p.m., Hallmark) salutes four selfless individuals.

¢ Presidential candidate Sen. John McCain makes a brief cameo in the 2005 summer comedy “Wedding Crashers” (8 p.m., TBS), starring Vince Vaughn and Owen Wilson.

¢ On two episodes of “Numb3rs” (CBS), a cult leader evades capture (8 p.m.), danger at sea (9 p.m.).

¢ Scheduled on “20/20” (9 p.m., ABC): a repeat 2007 report on children who question their gender.